ISOTHERMS, KINETICS AND THERMODYNAMICS STUDIES ON THE SEQUESTRATION OF EOSIN YELLOW FROM AQUEOUS SOLUTION USING CUBAN PALM FRUİT PERİCARP AS A LOW-COST ADSORBENT

Abstract

The environmental hazard caused by synthetic dyes on aquatic ecosystems has necessitated an intensified demand for more sustainable and affordable methods to mitigate their impacts. This study explored the efficiency of Cuban palm fruit pericarp (CPFP) as a readily available and eco-friendly adsorbent for removing Eosin yellow from aqueous solution. The adsorbent was characterized by Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy, Brunauer-Emmett Teller analysis and pHPZC determination. Batch adsorption experiments were conducted to optimize various parameters including adsorbent dosage, pH, agitation speed, temperature, initial dye concentration, ionic salt concentration, and contact time. Changes in the surface properties of the adsorbent before and after adsorption confirmed Eosin yellow adsorption and the involvement of surface functional groups in the process. The maximum sorption capacity of the adsorbent was 135.320 mgg-1, with optimal sorption at pH 3, 120 min contact time, 348 K, 100 mg adsorbent/150 mL dye solution, and 150 rpm agitation speed. Both Temkin and Langmuir isotherms as well as pseudo-second order kinetics model best described the adsorption behavior, with intra-particle diffusion playing a role but not as the sole limiting step. Negative values of standard Gibb’s free energy change (ΔGo) indicated high feasibility and spontaneity of the adsorption process, while positive values of standard enthalpy change (ΔHo) confirmed the endothermic nature of the process. Application of CPFP adsorbent for treating real textile wastewater demonstrated significant decolorization and
reduction in pollution loads. This study underscores the efficiency of CPFP as an affordable and eco-friendly option for effective treatment of toxic dye-contaminated wastewater.